1979 年 99 巻 1 号 p. 51-58
We investigated the effects of oral administration of seven antibiotics and six chemotherapeutic agents on ureolysis in rats by 1) measuring 14CO2 expired in breathing air after oral administration of 14C-urea (in vivo measurement) and by 2) determining urease activity of the ileum-caecum contents of treated rats (in vitro measurement). Urease activity of the ileum-caecum contents was not directly inhibited by these drugs. When antibiotics were administered orally, ureolysis was most strongly depressed by clindamycin, followed by cefazolin, thiophenycol and neomycin, in descending order of depression. The depression percentages of these antibiotics in in vivo and in vitro measurements were 50-76% and 56-96%, respectively."The antibiotics mixture"completely depressed ureolysis in in vivo and in vitro measurements. The antibiotics used inhibited the growth of urease-positive bacteria in the intestinal flora of rats and their depressive effects depended on their antibacterial characteristics. When sulfanilamide- or nitrofuran derivatives were administered, ureolysis in in vivo and in vitro measurements was not depressed but rather, activated. The administration of metronidazole depressed ureolysis in some rats and not in others, possibly due to a difference in the intestinal flora of several urease-positive bacteria. The administration of berberine, lactulose and pectic acid did not affect ureolysis.